In-hospital outcomes of neonates with hypoxic-ischemic encephalopathy receiving extracorporeal membrane oxygenation

Bleeding Complications in Neonates Receiving Extracorporeal Membrane Oxygenation and Controlled Hypothermia

OBJECTIVE

 Safety and efficacy data on controlled hypothermia (CH) for neonates with moderate to severe hypoxic ischemic encephalopathy has been extrapolated to a subgroup of these patients who also require extracorporeal membrane oxygenation for refractory persistent pulmonary hypertension of the newborn (PPHN). However, safety data on the concomitant use of CH and extracorporeal membrane oxygenation (ECMO) are lacking.

METHODS

 This is a single-center retrospective study of neonates ≥35 weeks' gestation with refractory PPHN who required ECMO between January 2010 and December 2020. Study groups were divided into those receiving CH/ECMO versus ECMO only. Baseline characteristics, short-term outcomes, and brain magnetic resonance imaging (MRI) data were compared.

RESULTS

 A total of 36 neonates who received ECMO for refractory PPHN were included. Of these, 44.4% (n = 16) received CH/ECMO and 55.6% (n = 20) received ECMO only. Bleeding complications were more common in CH/ECMO group 50% (n = 8) versus ECMO only 15% (n = 3, p = 0.023). T1 brain MRI severity scores were higher in CH/ECMO group versus ECMO only group, however, there were no statistical difference in T2 and diffusion-weighted image scores. Functional status and survival to discharge were comparable between groups.

CONCLUSION

 In our cohort, neonates who received CH/ECMO had higher bleeding complications than ECMO only group with comparable functional status and survival at discharge.

KEY POINTS

· Safety data on the concomitant use of CH and ECMO are lacking in neonates.. · In our cohort, neonates who received CH/ECMO had higher bleeding complications than ECMO only group.. · Functional status and survival to discharge were no differences between the two groups..

Asphyxia, Therapeutic Hypothermia, and Pulmonary Hypertension

Neonates with a perinatal hypoxic insult and subsequent neonatal encephalopathy are at risk of acute pulmonary hypertension (aPH) in the transitional period. The phenotypic contributors to aPH following perinatal asphyxia include a combination of hypoxic vasoconstriction of the pulmonary vascular bed, right heart dysfunction, and left heart dysfunction. Therapeutic hypothermia is the standard of care for neonates with moderate-to-severe hypoxic ischemic encephalopathy. This review summarizes the underlying risk factors, causes of aPH in neonates with perinatal asphyxia, discusses the unique phenotypical contributors to disease, and explores the impact of the initial insult and subsequent therapeutic hypothermia on aPH.

Extracorporeal Membrane Oxygenation Then and Now; Broadening Indications and Availability

Extracorporeal membrane oxygenation (ECMO) is a life support technology provided to children to support respiratory failure, cardiac failure, or cardiopulmonary resuscitation after failure of conventional management. Over the decades, ECMO has expanded in use, advanced in technology, shifted from experimental to a standard of care, and evidence supporting its use has increased. The expanded ECMO indications and medical complexity of children have also necessitated focused studies in the ethical domain such as decisional authority, resource allocation, and equitable access.

Update on pre-ECMO evaluation and treatment for term infants in respiratory failure

The epidemiology, diagnostic and management approach to severe hypoxemic respiratory failure in the term and near-term neonate has evolved over time, as has the need for extracorporeal membrane oxygenation (ECMO) support in this patient population. Many patients who historically would have required ECMO support now respond to less invasive therapies, with patients requiring ECMO generally representing a higher risk and more heterogenous group of underlying diagnoses. This review will highlight these changes over time and the current available evidence for the diagnosis and management of these infants, as well as the current indications and relative contraindications to ECMO support when oxygen delivery cannot meet demand with less invasive management.

Changing populations being treated with ECMO in the neonatal period - who are the others?

Extracorporeal life support via extracorporeal membrane oxygenation (ECMO) has served the sickest of neonates for almost 50 years. Naturally, the characteristics of neonates receiving ECMO have changed. Advances in care have averted the need for ECMO for some, while complex cases with uncertain outcomes, previously not eligible for ECMO, are now considered. Characterizing the disease states and outcomes for neonates on ECMO is challenging as many infants do not fall into classic categories, i.e. meconium aspiration syndrome (MAS), respiratory distress syndrome (RDS), or congenital diaphragmatic hernia (CDH). Since 2017, over one third of neonatal respiratory ECMO runs reported to the Extracorporeal Life Support Organization Registry are grouped as Other, a catch-all that encompasses those with a diagnosis not included in the classic categories. This review summarizes the historical neonatal ECMO population, reviews advances in therapy and technology impacting neonatal care, and addresses the unknowns in the ever-growing category of Other.

Venovenous versus venoarterial extracorporeal membrane oxygenation among infants with hypoxic-ischemic encephalopathy: is there a difference in outcome?

OBJECTIVE

Our hypothesis was that among infants with hypoxic-ischemic encephalopathy (HIE), venoarterial (VA), compared to venovenous (VV), extracorporeal membrane oxygenation (ECMO) is associated with an increased risk of mortality or intracranial hemorrhage (ICH).

DESIGN/METHODS

Retrospective cohort analysis of infants in the Children's Hospitals Neonatal Database from 2010 to 2016 with moderate or severe HIE, gestational age ≥36 weeks, and ECMO initiation <7 days of age. The primary outcome was mortality or ICH.

RESULTS

Severe HIE was more common in the VA ECMO group (n = 57), compared to the VV ECMO group (n = 53) (47.4% vs. 26.4%, P = 0.02). VA ECMO was associated with a significantly higher risk of death or ICH [57.9% vs. 34.0%, aOR 2.39 (1.08-5.28)] and mortality [31.6% vs. 11.3%, aOR 3.06 (1.08-8.68)], after adjusting for HIE severity.

CONCLUSIONS

In HIE, VA ECMO was associated with a higher incidence of mortality or ICH. VV ECMO may be beneficial in this population.

Hemodynamic optimization for neonates with neonatal encephalopathy caused by a hypoxic ischemic event: Physiological and therapeutic considerations

Neonatal encephalopathy due to a hypoxic-ischemic event is commonly associated with cardiac dysfunction and acute pulmonary hypertension; both therapeutic hypothermia and rewarming modify loading conditions and blood flow. The pathophysiological contributors to disease are complex with a high degree of clinical overlap and traditional bedside measures used to assess circulatory adequacy have multiple confounders. Comprehensive, quantitative echocardiography may be used to delineate the relative contribution of lung parenchymal, pulmonary vascular, and cardiac disease to hypotension and/or hypoxemic respiratory failure. In this review, we provide a detailed overview of the contributors to hemodynamic instability following perinatal hypoxic-ischemic injury. Our proposed approach to therapy focuses on physiopathological considerations with interventions individualized to this potentially complex condition and considers the pharmacological idiosyncrasies, which may occur among neonates with NE presenting with multiorgan dysfunction while undergoing therapeutic hypothermia.

Noninvasive neurocritical care monitoring for neonates on extracorporeal membrane oxygenation: where do we stand?

OBJECTIVE

To determine practice variation in the utilization of neuromonitoring modalities in neonatal extracorporeal membrane oxygenation (ECMO) patients across Level IV neonatal intensive care units (NICUs).

STUDY DESIGN

Cross-sectional survey design using electronic surveys sent to site sponsors of a multicenter collaborative of 34 Level IV NICUs of the Children's Hospitals Neonatal Consortium (CHNC) from June to August 2018.

RESULTS

We had 22 survey respondents from CHNC ECMO centers. Twenty-seven percent of respondents routinely monitored for seizures using electroencephalogram. Cerebral near infrared spectroscopy was used by 50%. Head ultrasound was performed by 95% but the frequency, duration, and type of views varied. Post ECMO screening brain MRI prior to hospital discharge was routinely performed by 77% of respondents. A majority of centers (95%) performed neurodevelopmental follow-up after hospital discharge.

CONCLUSIONS

There is variation in neuromonitoring practices in Level IV NICUs performing ECMO. Lack of evidence and clear outcome benefits has contributed to practice variation across institutions.

Outcomes of infants with hypoxic ischemic encephalopathy and persistent pulmonary hypertension of the newborn: results from three NICHD studies

OBJECTIVE

To determine the association of persistent pulmonary hypertension of the newborn (PPHN) with death or disability among infants with moderate or severe hypoxic ischemic encephalopathy (HIE) treated with therapeutic hypothermia.

METHODS

We compared infants with and without PPHN enrolled in the hypothermia arm from three randomized controlled trials (RCTs): Induced Hypothermia trial, "usual care" arm of Optimizing Cooling trial, and Late Hypothermia trial. Primary outcome was death or disability at 18-22 months adjusted for severity of HIE, center, and RCT.

RESULTS

Among 280 infants, 67 (24%) were diagnosed with PPHN. Among infants with and without PPHN, death or disability was 47% vs. 29% (adjusted OR: 1.65, 0.86-3.14) and death was 26% vs. 12% (adjusted OR: 2.04, 0.92-4.53), respectively.

CONCLUSIONS

PPHN in infants with moderate or severe HIE was not associated with a statistically significant increase in primary outcome. These results should be interpreted with caution given the limited sample size.

Organ Complications of Infants with Hypoxic Ischemic Encephalopathy Before Therapeutic Hypothermia

Hypoxic ischemic encephalopathy (HIE) is a serious neurological complication that may develop in asphyxiated infants. Severity of encephalopathy may vary, and concurrent multiorgan dysfunctions are commonly observed. Analyzing the incidence of such complications according to severity of HIE, and how they correlate with each other, may shape clinical judgment and allow for early intervention. The study included a total of 57 HIE infants, in which 27/57 (47.37%) met Sarnat inclusion criteria for moderate stage II HIE (Group A) and 30/57 (52.63%) for severe stage III HIE (Group B). Both groups were assessed and compared for incidence of kidney dysfunction, liver dysfunction, coagulopathy, qualitative cardiac abnormalities, respiratory-related dysfunction, and bone marrow insufficiency/thrombocytopenia. All assessments were performed before initiation of therapeutic hypothermia. The complications were further assessed for the presence of correlations. Group B experienced significantly higher incidence of kidney dysfunction (A: 2/27 [7.4%] vs. B: 21/30 [70%], p < 0.001), liver dysfunction (A: 14/27 [51.8%] vs. B: 28/30 [93.3%], p < 0.001), and thrombocytopenia (A: 8/27 [29.6%] vs. B 21/30 [70%], p = 0.002) in our study group. Kidney dysfunction and bone marrow insufficiency showed the highest affiliation with other organ systems in both groups, correlating positively with each other as well as HIE severity, cardiac abnormalities, liver dysfunction, and infant death. A total of 8/57 (14%) infant deaths were observed, all originating from grade III severe HIE group (p = 0.003). Multiorgan dysfunction showed a significant difference between HIE severity (A: 12/27 [44.4%] vs. B: 28/30 [93.3%], p < 0.001). A positive correlation was obtained between multiorgan dysfunction, HIE severity, and infant death. Stage III HIE infants are more likely to experience abnormalities in the kidneys, liver, bone marrow as compared with stage II HIE infants. Correlations between organ complications are present, and should be taken into account during clinical assessment of HIE infants. The probability of mortality is higher in stage III HIE infants with observed multiorgan dysfunctions.

Neonatal respiratory extracorporeal membrane oxygenation and primary diagnosis: trends between two decades

OBJECTIVE

Examine changing neonatal respiratory extracorporeal membrane oxygenation (ECMO) practice trends and outcomes.

STUDY DESIGN

Retrospective cohort study comparing neonatal respiratory ECMO in the 1990 and 2010 decades (1994-1995 and 2014-2015). Patients ≤ 30 days of life, reported to the Extracorporeal Life Support Organization registry, were included.

RESULTS

Four thousand one hundred and twenty-five patients met inclusion criteria. ECMO cases decreased by 33%. The primary ECMO diagnosis changed significantly over time (p < 0.0001). Survival to discharge decreased (76 vs 67%, p < 0.0001) and ECMO duration increased (131 vs 158 h, p < 0.001). Lung recovery was the most common reason to discontinue ECMO although family request for withdrawal and a diagnosis considered "incompatible with life" was increasingly common in the 2010s.

CONCLUSION

Although the use of ECMO for neonatal respiratory diagnoses has decreased over time, its use has increased for patients with more complex diagnoses and ECMO duration is longer. ECMO continues to be an important supportive therapy, improved understanding of which patients would benefit most is needed.

Case series of therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy during extracorporeal life support

Therapeutic hypothermia initiated within 6 hours of birth is currently the standard of care for the management of neonates with hypoxic-ischemic encephalopathy. Neonates undergoing therapeutic hypothermia for hypoxic-ischemic encephalopathy are also at risk for severe respiratory failure and need for extracorporeal life support. The risks and benefits of therapeutic hypothermia for hypoxic-ischemic encephalopathy during extracorporeal life support are still not well defined. We report our experience of a case series of six neonates who underwent therapeutic hypothermia for hypoxic-ischemic encephalopathy during extracorporeal life support. We also report long-term neurodevelopmental follow-up from 6 to 24 months and add to the current body of evidence regarding feasibility, clinical experience, and short-term complications.